diff --git a/Products/zms/standard.py b/Products/zms/standard.py
index 403c259c5..22e6fd37b 100644
--- a/Products/zms/standard.py
+++ b/Products/zms/standard.py
@@ -72,6 +72,9 @@ def pystr(v, encoding='utf-8', errors='strict'):
       v = str(v)
   return v
 
+security.declarePublic('pybytes')
+# Just for compatibility of old ZMS4 templates.
+pybytes = pystr
 
 # Umlauts
 umlaut_map = {